1. Field of the Invention
This invention relates to a brake-slip-controlled automotive vehicle brake system.
2. Description of the Relevant Art
In such automotive vehicle brake systems a change-over valve is generally connected, via one of its connections, to a vacuum source of the automotive vehicle. The vacuum source can be, for example, formed by the suction pipes of the engine. The other connection is generally connected to the atmospheric pressure so that the actuation of the pressure modulator is effected by the difference between atmospheric pressure and vacuum.
Upon detection by a brake slip control circuit of wheel slip at any one of the vehicle's wheels during braking, the change-over valve will be switched so that its piston-and-cylinder arrangement will cause the volume receivers to receive an increased volume of fluid resulting in a reduction in the braking pressure. At the same time, closing valves of the individual wheel brake circuits are operated in a pulse-like manner so that there will be a braking pressure reduction only in the brake circuits of the wheels showing wheel slip.
It is an object of the present invention to provide a brake-slip-controlled automotive vehicle brake system of the type referred to above which also permits traction slip control of the vehicle's driven wheels by means of slight constructional modification while fully making use of the components already provided.